Composite active material

Abstract

Provided is a composite active material that is capable of more suppressing deterioration of an active material caused by the moisture of the composite active material than a conventional composite active material by increasing a permissible water content of a layer of the composite active material. The composite active material that is used for solid-state batteries includes: an active material; a first coat layer that contains a fluoride-containing first solid electrolyte, the first coat layer coating at least part of a surface of the active material; and a second coat layer that contains a sulfide-containing second solid electrolyte, and a solvent, the second coat layer coating at least part of the first coat layer, wherein a water content of the composite active material at 200° C. measures at most 823 ppm on a Karl Fischer titrator.

What is claimed is: 
     
         1 . A composite active material that is used for solid-state batteries, the composite active material comprising:
 an active material;   a first coat layer that contains a fluoride-containing first solid electrolyte, the first coat layer coating at least part of a surface of the active material; and   a second coat layer that contains a sulfide-containing second solid electrolyte, and a solvent, the second coat layer coating at least part of the first coat layer, wherein a water content of the composite active material at 200° C. measures at most 823 ppm on a Karl Fischer titrator.   
     
     
         2 . The composite active material according to  claim 1 , wherein
 the water content of the composite active material at 200° C. measures at least 10 ppm on a Karl Fischer titrator.   
     
     
         3 . The composite active material according to  claim 1 , wherein
 in the water content of the composite active material, a water content of the second coat layer is higher than a water content of the first coat layer.